You Buy 'em Books ...

"Aunt Nora, do you know anything about a playwright named Thomas Watson?" The voice of Saffa Moore cut plainly through the background noise, climbing stridently across the double bookshelf of the Watts-Amata U. bookstore and wildlife emporium.
"Yes," Nora Shekrie replied, "he was one of the most important writers of Shakespeare's day." Nora returned to browsing for a used copy of "The Compleat Strategyst" -- she had long ago learned that Saffa did not appreciate answers much beyond the scope of her original question. She finally located a copy with all the pages intact and placed it in her basket.
"Aunt Nora, Columbus was Portuguese, right?"
"He was from Genoa; it's part of Italy today. He sailed to the New World under the Spanish flag."
"Oh. And Portugal got into a lot of wars back then?"
"Enough to get a reputation."
"Dude." Saffa's inflection was more acknowledgement than comment.
Nora worked her way down the aisle, finding a dog-eared copy of Zelazny's last Amber novel; that joined the J.D. Williams classic.
"And Percy Shelley was a writer?"
"Yes, Saffa." Nora tried to keep the fatigue out of her voice.
"Sorry, Aunt Nora. You want to come look at this collection?"
Nora walked around the end of the aisle and back to where Saffa stood in front of the discount books. She looked at the boxed set Saffa had in her hand and stifled a laugh.
"I thought it might be good to get some culture in my bed-time reading." Nora contemplated the four titles:
"Collected Plays of Thomas Watson, 1574-1589"
"Columbus: the Compleat Letters in Italian"
"History of the English-Portuguese Wars, 1260 to present"
"The Ghost Stories of Percy Bysshe Shelley"

"Well," she ventured after a few seconds, "have you ever wanted to become an author?"
"Sure. Hasn't everyone?"
"Granted. Do you keep a diary?"
"No, but I was planning to start one on the first of the month."
"Then I'd say these will be a worthy investment. Since they're on clearance, I'll buy them as an early birthday present."

When Saffa opened the first volume that night, she was quite surprised at the contents. She decided to start her diary immediately.

What was the catch?

Hint

Answer

Those are "gag" titles: the books were all blank pages in a nice cover. Saffa used the Watson volume as her second-year diary, and is saving the others for a series of brain teasers.
Although Thomas Watson was one of the most influential and popular playwrights of the Elizabethan era (ranking almost as high as Shakespeare and Bacon), not one of his plays survives today. Quotes, yes; entire plays, no.
Columbus grew up in Genoa and did much early seafaring for Portugal, all of his known writings are in Spanish alone.
England and Portugal have never gone to war against one another.
Finally, although Percy Shelley did start a ghost story once, he never finished. In fact, on that occasion, Lord Byron got nowhere with his entry. Dr. John W. Poldari wrote little on his own idea, but eventually turned Byron's start into "The Vampyre", recognized as the first vampire novel. The last member of the retreat, Mary Wollstonecraft Godwin, was the only member of the group to finish her story. Two years later, after marrying Percy, she published her offering: "Frankenstein".Hide